1. Field of the Invention
This invention relates to generation of a Artificial Ionospheric Mirror (AIM), or a plasma layer in the atmosphere. The AIM is used like the ionosphere to reflect RF energy over great distances.
2. Description of the Related Art
In the past, the technique of using the ionosphere as a mirror to reflect radio waves, or RF energy, has given Ham Radio operators the ability to send transmissions over long distances. This technique has also provided radar systems the ability to look "over the horizon." Variations and fluctuations in the ionosphere, however, can render the effectiveness of such communications uncertain. Thus, the desirability of creating controllable plasma layers in the atmosphere for communications purposes has been recognized. See, for example, U.S. Pat. No. 4,686,605 issued to Eastlund and U.S. Pat. No. 4,712,155 issued to Eastlund et al.
Previous experiments directed toward creating plasma layers for communications have suffered from the inability to control the inclination of the plasma layer so that signals could be transmitted and received from various ranges. In other words, while one could create a plasma layer in the atmosphere at a lower altitude than the ionosphere, point to point communications would be limited in range based on the reflection angles of the transmitted and reflected signals.